Dave Jones

issue will be if and when you sell, you will need an MCS cert.

fancoils over UFH for 1st floor / bedrooms all day long. free air con.

architects have been doing this (badly) for years.

be careful, building over sewers is picked up during conveyancing and will scupper a sale.

Don't believe the maintenance free claim on these. A neighbor has some, yes it doesnt rot and get as dirty as wood. But it does move more and need adjusting every summer after it swells up. All the nice lined up gaps are all over the place.

the structural opening is the stop end. DPC is to stop damp climbing, it cant there is an opening. A tray is to deflect moisture falling down the cavity above, it cant there isnt one.

with the latest levels of insulation it will be plenty. we had days of 37c last summer. constant 20 in the house for free from the solar.

mine is hung from a wall, zero vibes.

no, i dont want the loop to be less than 15c to avoid dewpoint on the slab.

add another block to the inside skin and have a normal gutter. box gutters = ongoing maintenance every year, clearing moss/leaves. it wont be the architect who does that.

have you got MVHR or trickle vents ? ICF should be very good for no leakage would have thought. Whats your heating req in m2 in watts ? gut feeling is your 50% overspeccing the ashp. it should never have to run a defrost cycle if used properly. mine never has.

drill baby drill. Reform will sort.

remove all zoning controls (if any fitted), 8kw sounds very large, what do the heat loss calcs say the engineer has provided to you backing up his design of 8kw being required ?

i tried also, octopus refused without MCS cert. How did you manage it ?

the problem with self install is no MCS paperwork. Octopus wouldnt accept any export from me (for payment) without it.